Safety cutting device

ABSTRACT

A safety cutting device includes a slidable insert that moves longitudinally within a cavity of a housing. The slidable insert has a cutting blade attached and moves within the housing from a safe position in which the blade is covered to an exposed position for cutting. The safety device has a release button positioned near an anterior end of the housing. A biasing member automatically retracts the blade when the release button is activated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/201,658, filed on Mar. 7, 2014, which is a continuation ofInternational Application No. PCT/US2013/073433, filed on Dec. 5, 2013,which claims the benefit of and priority to U.S. Provisional ApplicationNo. 61/733,433, filed on Dec. 5, 2012, the entireties of each of whichare incorporated herein by reference.

BACKGROUND Field of Use

The present invention relates to cutting devices such as safety scalpelsand safety cutting devices.

Related Technology

Surgical scalpels are used by medical personnel in connection withsurgical procedures ranging from simple out-patient procedures toextraordinarily complex procedures carried out under general anesthesia.When working with such a sharp instrument, there is always a danger tomedical personnel of inadvertent puncture of the skin. Aside from theinjury itself, the more important concern for the punctured individualrelates to the potential spread of disease from a non-sterileinstrument.

The use of surgical scalpels having a retractable blade has beensuggested as a means for reducing the number of such puncture wounds.Indeed, a number of patents have been issued which are directed towardsurgical scalpels having retractable blades. These include, for example,U.S. Pat. Nos. 5,503,262; 5,571,128; 5,569,282; 6,589,258; 6,645,216;and 6,949,109.

A tremendous effort has been made to make cutting devices that willimprove safety in health care and industry. Government agencies such asOSHA have mandated the use of safer cutting devices. The industryincluding large medical device manufacturers and small entrepreneurialcompanies and individuals have attempted to produce devices that improvesafety. However, studies have shown that the industry thus far hasfailed. For example, an industry published journal “OR Manager”published the following statement: “The products just aren't there.Unfortunately, it's hard to be compliant when we don't have goodtechnology.” See OR Manager Vol. 21, No. 12, December 2005, p. 3.Indeed, data shows that current safety scalpels are actually not saferthan traditional reusable scalpels. see Vose, J. et al., “ReducingScalpel Injuries in the OR,” AORN Journal, Vol. 90, No. 6 (December2009), p. 869. Thus, there exists a long felt but unmet need forimproved safety scalpels that can reduce sharps injuries.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an elevational view of a safety cutting device with the bladein a covered position according to one embodiment of the invention;

FIG. 1B is an elevational view of the cutting device of FIG. 1A with theblade in an exposed position;

FIG. 1C is an elevational view of the cutting device of FIG. 1A withblade in an exposed position and a release button actuated;

FIG. 2 illustrates an exploded view of the cutting device of FIG. 1A;

FIG. 3A is a partial cutaway view of the cutting device of FIG. 1A in acovered position and showing the engagement of a slidable insert supportand a portion of a housing;

FIG. 3B illustrates the partial cutaway view of FIG. 3A with the cuttingdevice in an exposed position;

FIG. 3C illustrates the partial cutaway view of FIG. 3A with the bladein an exposed position and the release button in an actuated position;and

FIG. 4 shows a partial exploded view of the cutting device of FIG. 1Ashowing the slidable insert, spring, and assembled housing.

DETAILED DESCRIPTION

The present invention relates to safety cutting devices. The devices ofthe present invention have one or more improved mechanisms foractivating and retracting the blade to make the cutting device safe whennot in use. The activation and retraction features are intuitive and inmany embodiments allow a clinician to operate the features using asingle hand without looking. In addition, the safety mechanisms in someembodiments can be implemented with a minimal number of parts, therebymaking the devices easy and economical to manufacture and assemble. Forexample, some embodiments can be manufactured with as few as 5 parts(e.g., a blade, a spring, and 3 injection molded pieces).

FIGS. 1A-1C and 2 illustrate an example safety cutting device 10according to one embodiment of the invention. Device 10 includes acutting blade 12 connected to a slidable insert 14. Slidable insert 14is configured to move within an elongate housing 16. Elongate housing 16includes a cavity 18 (FIG. 4) that extends between an anterior opening20 at an anterior end 22 of housing 16. A posterior opening 24 is formedat an opposite end of housing 16 in longitudinal direction.

Housing 16 forms a sheath 30 that is configured to house the blade andprotect it from cutting a person. Sheath 30 defines the anterior opening20 through which cutting blade 12 can be extended to expose cuttingblade 12 and allow device 10 to be used as a cutting instrument.

The slidable insert 14 and the housing 16 are configured with any numberof walls, grooves, ridges, protrusions and/or indentations to allowslidable insert 14 to move within housing 16 in a slidable mannerbetween a safe position in which cutting blade 12 is within sheath 30and an exposed position in which cutting blade 12 is extended throughanterior opening 20. The direction of movement of slidable insert 14 maybe in the longitudinal direction 28 (identified by arrow 28 in FIG. 2),which is preferably along the longitudinal axis of elongate housing 16(either forward or backward).

Unless otherwise specified, the anterior opening is the furthestanterior point on the housing in the longitudinal direction from whichthe blade emerges during activation.

Unless otherwise specified, the posterior opening is the location on thehousing where a posterior activation mechanism (e.g., a back button)emerges from the housing. The posterior opening may be open in thelongitudinal direction or partially or completely opened toward a side,bottom, or top of the housing. Where the posterior activation mechanismincludes a longitudinal post the opening is preferably in thelongitudinal direction.

Unless otherwise specified, the longitudinal direction is the plane inwhich the slider moves when going from the safe position to the exposedposition or the exposed position to the safe position.

FIGS. 1A and 1B show blade 12 in the safe position and the exposedposition, respectively. Additional details regarding movement ofslidable insert 14 are described below with regard to FIGS. 3A-3C.

As shown in FIG. 2, housing 16 may be formed from a plurality ofindividual sections, such as left section 36 and right section 38. Anynumber of sections can be formed and can be attached in any known way tomake a cavity 18 suitable for slidable insert 14 to move inside housing16. Housing sections 36 and 38 may be joined by snap connects,ultrasonic welding, adhesive, or the like.

The junction of left section 36 and right section 38 may create a track34, half of which is visible in left section 36 of FIG. 2. Track 34 isconfigured to receive a biasing member 32. In some embodiment biasingmember 32 may be a coil spring that undergoes compression or extension.Slidable insert may have a spring connector 74 (e.g., a protrusion) forengaging biasing member 32. In other embodiments, the biasing member maybe positioned around or in slidable insert 14 and may be something otherthan a coil spring.

In some embodiments, with slidable insert 14 in the exposed position,housing 16 may engage slidable insert 14 on multiple sides to providestability for blade 12. For example, slidable insert may contact sheath30 on at least 3, preferably 4 sides so as to stabilize blade 12relative to housing 16. The engagement can be achieved by tapering theinside surfaces of sheath 30 of housing 16. In some embodiments anteriorend 22 of housing 16 may taper on an inside surface to decrease thetolerances between slidable insert 14 and housing 16 with the slidableinsert in the exposed position. Decreasing the tolerances at anteriorend 22 reduces wiggle or play in the blade relative to the housing. Insome embodiments, the tolerances may be less than or equal to 0.010,0.007, or 0.005 inch. The tolerances can be selected in a vertical or ahorizontal direction (where the vertical direction is parallel to theplane of the blade).

In some embodiments sheath 30 may be tapered on an outside surface toreduce the width of housing 16 near anterior end 22. Tapering on theoutside near anterior end 22 provides greater visual access to thetissue or object being cut by the blade.

Blade 12 may be connected to slidable insert by heat staking a raisedportion 41 of slidable insert to blade 12. Alternatively, slidableinsert 14 may be injection formed around blade 12.

Device 10 includes a posterior activation mechanism 40 that includes alongitudinal post 42 and a rearward facing engagement surface 44. Aprotective cover 46 extends from posterior opening 24 to a posterior end48 of protective cover 46, which is also a posterior end 48 of housing16 and device 10. Protective cover 46 can also include lateralextensions 92 a and 92 b.

Housing 16 and slidable insert 14 can include components sufficient toform one or more latches or locking mechanism to hold slidable insert 14in the extended position (i.e., against the biasing member). In someembodiments, moving slidable insert 14 from the safe position to theexposed position automatically actuates the latching mechanism. In someembodiments the components of a latch include an anterior protrusion 50on a deflectable member 52 of slidable insert 14. Protrusion 50 isconfigured to engage a latch surface 54 of housing 16. Device 10 mayalso include components for releasing a latch or lock mechanism. Forexample, device 10 may include a release button 56 extending fromhousing 16 through flange 58. Release button 56 may include a protrusion60 that engages anterior protrusion 50 to cause deflection of member 52of slidable insert 14 to release the latch.

Device 10 may include a second locking mechanism formed from housing 16and slidable insert 14. Second locking mechanism may be formed betweenprotrusion 60 of release button 56 that engages a lock surface 62 ofslidable insert 14.

Slidable insert 14 may also include components that facilitate simpleassembly. In the embodiment illustrated in FIG. 2, slidable insert 14include a posterior deflectable member 64 having a protrusion 66. Anassembly protrusion 68 on housing 16 is configured to deflect member 64on assembly and engage protrusion 68 to prevent slidable insert 14 frombeing ejected from cavity 18 after assembly.

FIGS. 3A-3C illustrate the scalpel with a portion of the housing removedto reveal the mechanisms of activation, latch release, and slidableinsert in a safe position, latched position, and locked position,respectively. In FIG. 3A, device 10 has slidable insert 14 in a safeposition. Blade 12 is within sheath 30, which provides protectionagainst a person being cut by cutting edge 70 of blade 12.

Biasing member 32, which may be a coil spring in some embodiments, sitsin track 34 and biases slidable insert 14 in the safe position. Biasingmember 32 has a back end 72 that engages connector 74 of slidable insert14 (e.g., a longitudinal pin). A front end 76 of biasing member 32engages end wall 78 of track 34. Track 34 may be formed from theassembly of left and right sections of housing 16, each of whichincludes a portion of the track. Although forming the track from twopieces is not required. Slidable insert 14 is moveable in thelongitudinal direction 28 toward the anterior end 22. FIG. 3B showsdevice 10 with slidable insert 14 in the exposed position. As shown bythe difference between FIGS. 3A and 3B, a forward movement of slidableinsert 14 in the longitudinal direction causes biasing member 32 tocompress, thereby increasing or maintaining the biasing force (in thiscase compression) as the slidable insert moves into the exposedposition. Thus, absent a locking mechanism slidable insert is pushedback towards the safe position. The spring force can be selected toensure the friction caused by the selected tolerances does not cause theslidable insert to stick when the latch mechanism is released.

In some embodiments, housing 16 and slidable insert 14 automaticallyform a lock when slidable insert 14 is moved into the exposed position.As slidable insert 14 is moved forward, anterior protrusion 50positioned on or near the end of deflectable member 52 engagesprotrusion 54 of housing just as blade 12 is nearing the extendedposition. Protrusion 50 on slidable insert 14 and protrusion 54 can haveanterior and posterior ramps, respectively such that the forwardmovement of slidable insert 14 causes the protrusions to engage in asliding manner. This sliding movement of the ramps forces deflectablemember 52 to flex and protrusion 50 to move downward, thereby passingover protrusion 54. However, once protrusions 50 and 54 pass one another(via the movement of slidable insert 14), deflectable member 52 snapsback. The anterior surface of protrusion 54 and the posterior surface ofprotrusion 50 are relatively parallel to one another, which causes themto lock when biasing member 32 pushes slidable insert 14 backward. Thismechanism often produces a “click” sound, which provides an audiblenotification to the user that the blade is in the exposed position. Thismechanism is also referred to herein as a “click latch mechanism.”Although not required, in some cases an audible or tactile feedback ofactivation may be very important for a clinician to be assured that thedevice is in the proper configuration before attempting to cut,particularly since the slidable insert is biased to move out of theexposed position.

As shown in FIG. 3C, device 10 may include a release button 56 torelease the latch mechanism locking slidable insert 14 in the exposedposition. Release button 56 includes a protrusion 60 that when moveddownward engages protrusion 50 and forces deflectable member 52 downwarda sufficient distance to release the latch between protrusion 50 onslidable insert 14 and protrusion 54 on housing 16.

In some embodiments, protrusion 60 includes an anterior surface 80 thatcan engage a locking surface 62 on slidable insert 14 when releasebutton 56 is activated. Locking surface 62 may be a substantiallyperpendicular wall of slidable insert 14 (perpendicular to thelongitudinal direction). FIG. 3C shows release button with deflectablemember 52 deflected downward and protrusion 60 contacting surface 62 soas to lock slidable insert 14 in the exposed position even though thelatch mechanism has been deactivated. This dual locking function allowsa user to automatically activate the latch mechanism and change handposition without the blade retracting. Actuating release button 56releases the lock mechanism involving surface 62 and then releasingrelease button 56 disengages protrusion 60 from surface 62, therebyreleasing the lock on slidable insert 14 and allowing biasing member 32to automatically return slidable insert 14 to the safe position, whichreturns device 10 to the position illustrated in FIG. 3A.

Release button 56 may be biased to the non-actuated position (e.g., theposition shown in FIGS. 3A and 3B. Any biasing means may be used. In theembodiment shown in FIG. 3A, biasing may be achieved by creating button56 with a flange 58. Flange 58 may be an integral and/or continuousextension of the housing material. The thickness and/or length of flange58 may be selected to enable deflection of the button by a user. Thoseskilled in the art will recognize that the thickness and length of theflange will depend on the type of material being used and the desiredrigidness of the release button. In some embodiments, the thickness isless than 4, 2, or 1 mm and/or greater than 0.5, 1, or 1.5 mm or withina range thereof. The length of flange 58 may be greater than or equal to5, 10, or 15 mm and/or less than 35, 30, or 25, and/or within a range ofthe foregoing. By forming the button as a single piece with the housing,the number of parts that need to be produced and assembled can beminimized.

Housing 16 is configured to provide a handle 80 (FIG. 1) for the user tohold device 10. Handle 80 allows a user to grip the device for actuatinga posterior activation mechanism (e.g., a back button) 40 and actuatinga safety release mechanism 56, and/or manipulating device 10 during acutting procedure.

The configuration of handle 80 and the position of the release andactivation mechanisms (e.g., back button 40 and/or release button 56)relative to handle 80 is important in some embodiments to making device10 intuitive to activate and/or make safe (i.e., retract blade 12).Placing posterior activation mechanism 40 in a position posterior tohandle 80 allows activation similar to a pen. Or in other words, whengripping handle 80 a user's thumb is in a position to actuate theactivation mechanism 40; after actuating mechanism 40 the usertransitions the anterior end 22 to a position between the index, middle,and thumb fingers. While this transition requires significantmanipulation of the device, the muscle memory for performing themanipulation is well-known to essentially every clinician due to theubiquity of click pens. Moreover, Applicant has found that manipulatingthe device prior to making a cut versus after a cut is more acceptableto clinicians because attention to the patient is more urgentimmediately after making an incision. Placing the release mechanism onan anterior portion of housing 16 allows the clinician to release themechanism with minimal manipulation. Applicant has surprisingly foundthat placement of the release mechanism in the anterior portion of thedevice does not result in accidental deployment as one of skill in theart would expect.

Handle 80 may be made to have dimensions suitable for a person to graspthe handle and actuate the buttons. Handle 80 may be elongate with alength greater than or equal to 15, 20, 25, 30, 35, 45, or 55 mm longand/or less than or equal to 120, 100, 80, or 60 mm and/or within arange of any of the foregoing endpoints. In some embodiments, the handle80 of housing 16 can constitute the majority of the outer surface ofhousing 16. Handle 80 may include an front portion 82 (FIG. 1B) and aback portion 84 (FIG. 1B). For purposes of this invention, unlessotherwise specified, the front portion 82 is the front half of handle 80as measured in the longitudinal direction and the back portion 84 is theback half of handle 80. The handle portion 80 is the portion of thehousing that is useful as a gripping surface during use. In someembodiments, front portion 82 may have a length in the longitudinaldirection that is greater than or equal to 10, 15, 20, 25, 30, 35, or 40mm and/or less than or equal to 80, 60, 50, 40, or 30 mm, and/or withina range of the foregoing. Front portion 82 and sheath 30 form theanterior portion of housing 16.

Release button 56 may be positioned on the anterior portion of housing16 (i.e., sheath 30 and/or front portion 82). For example, releasebutton 56 may be positioned near anterior opening 20. Release button 56may be positioned less than or equal to 40, 35, 30, 25, 20, 15, or 10 mmand/or greater than 5, 10, 15, or 20 mm from anterior opening 20 insheath 30 and/or within a range of the foregoing. Release button 56 maybe positioned less than or equal to 50%, 45%, 40%, 35%, 30%, 25%, or 20%of the longitudinal distance from the anterior opening 20 to theposterior opening 24.

Positioning release button 56 on the anterior portion of housing 16and/or near anterior opening 20 makes the release button easy andintuitive to actuate. When a user's fingers are positioned formanipulating device 10 to perform a cutting procedure, the index fingerand/or thumb will be in contact with the anterior portion. Because thefingers are already located in the anterior portion of housing 16, auser can easily feel release button 56 with little to no hand movement.This tactile feedback allows a physician to actuate release button 56without repositioning the hand on handle 80.

Handle 80 may also serve as a grip for activating posterior activationmechanism 40. In this case, the fingers such as the index finger may bepositioned on the posterior portion of housing 16 (i.e., the thumb isextended rearward). The thumb may be placed on the rearward facingengagement surface 44 and drawn toward the back portion 84, therebyactuating mechanism 40.

Handle 80 may have any type of configuration suitable for providing aplace for a person to hold device 10 while actuating posterior mechanism40 or anterior release button 56. Handle 80 may have a cross sectionthat is contoured, circular, rectangular, or the like. The cross sectionof handle 80 may be elongate from top to bottom as compared to the width(e.g., oval or trapezoidal). In some embodiments, handle 80 may have anaverage thickness (i.e., distance in a direction transverse to blade 12)that is greater than or equal to 4, 5, 6, 8, or 10 mm and/or less thanor equal to 14, 12, 10, 8, or 6 mm or within a range of the forgoingendpoints. These thicknesses provide adequate space for a relativelylarge blade while still providing comfort and usability for an adult orclinician.

Handle 80 may also include gripping features to improve the feel and/ortexture of handle 80. For example, handle 80 may include texturizingthat gives the user a more tactile feel about where their hands arepositioned on handle 80. Handle 80 may also include a ruler 88 or otherindicia.

The sheath 30 and/or anterior opening 20 of housing 16 is configured toaccommodate the a relatively large blade. For example, blade 12 is astandard sized 11 blade, which has a blade height of 6.5 mm. In someembodiments, the housing 16 may accommodate a blade height of at least5, 6.5, or 7.5. The blade may a 10 blade, 11 blade, 15 blade, or otherstandard sized blade.

Sheath 30 can include a slot 90 that extend inward from anterior end 20.Slot 90 forms a suture cutting groove that allows a suture to be passedtherethrough when blade 12 is retracted (i.e., covered by sheath 30).Additional details regarding suture cutting grooves that can beimplemented in safety device 10 are disclosed in U.S. application Ser.No. 13/080,367, filed Apr. 5, 2011, which is hereby incorporated hereinby reference.

In some embodiments (were a relatively constant biasing force is neededor required), biasing member may be relatively long, preferably longerthan the distance slidable insert 14 travels between the safe positionand exposed position. For example, the length of biasing member 32 maybe at least 1.25, 1.5, 2, 2.5, or 3 times longer than the longitudinaltravel of slidable insert 14 between the safe position and the openposition. In some embodiments the biasing member 32 may be at least 15,20, 25, 30, 35, 45, or 55 mm long and/or less than 120, 100, 80, or 60mm and/or within a range of any of the foregoing endpoints. In someembodiments, biasing member extends at least 70%, 80%, or 90% of thedistance between anterior opening 20 and posterior opening 24 of cavity18 or a handle portion of housing 16. Relatively long biasing memberscan be advantageous for maintaining a similar bias at different lengthsof compression or extension.

The force of biasing member is selected to be greater than the frictionencountered when moving the slider from the exposed position to the safeposition. Biasing member 32 may be something other than a coil spring.For example, an elastic material may be used. In addition, the biasingmember may be under tension rather than compression. For example thehousing and slidable insert may each have a connector attached to thebiasing member. In this case, the slidable insert connector may beanterior to the housing connector such that forward movement of thesliding connector causes the biasing member to undergo tension ratherthan compression.

FIG. 4 illustrates device 10 partially assembled and showing aperspective view of posterior opening 24 leading to cavity 18. Device 10may be easily and economically assembled by inserting slidable insert 14into cavity 18, which is formed between left and right sections 36 and38 of housing 16. Prior to inserting slidable insert 14 into cavity 18,biasing member 32 is positioned in track 34. As slidable insert 14 isinserted into cavity 18, connector 74 on slidable insert 14 engages backend 72 of biasing member 32. Biasing member 32 is compressed in track 34until assembly protrusion 66 engages protrusion 68 on housing 16.Assembly protrusion 66 and protrusion 68 on housing 16 may have aforward facing ramp and reward facing ramp, respectively, such thatengagement of the protrusions causes assembly deflection member 64 to bedeflected downward as assembly protrusion 66 passes over protrusion 68on housing 16. Assembly protrusion 66 and protrusion 68 on housing 16have substantially parallel forward facing and rear facing surfaces,respectively. Once assembly protrusion 66 passes protrusion 68, rewardmovement of assembly protrusion 66 is inhibited by the substantiallyparallel surface.

Some embodiments include methods for assembling device 10. The methodcan include providing a slidable insert with an assembly protrusion. Themethod can include first assembling the housing to form a cavity for theslidable insert and then inserting the slidable insert into the cavity.

FIG. 4 shows a bottom portion of slidable insert 14 having ribs 97. Ribs97 can reduce friction and prevent slidable member 14 from sticking whenit retracts.

The cutting instruments described herein may be used in methods forperforming a cutting procedure. In some embodiments, the cuttingprocedure may be a procedure to cut live tissue. In other embodimentsthe cutting procedure may be a non-medical substrate. For example, thecutting devices described herein may be configured and used fornon-medical purposes such as cutting crafts, rope, string, cardboard,paper, and the like.

In some embodiments, housing 16 may include a pen clip that allowsdevice 10 to be clipped to a shirt pocket. Typically the clip openstoward an anterior end such that the blade is facing downward whenclipped to a pocket (e.g., a traditional shirt pocket).

The color and/or translucency of device 10 may assist some users inusing device 10. In some embodiments, sheath 30 and/or handle 80, and/orcover 46, may be made from a translucent material such as carbonate toallow the user to see the internal components of safety device 10.Sheath 30 may be translucent to reveal blade 12 when retracted.

Posterior Activation Mechanism with Anterior Release Mechanism

Some embodiments of the invention are directed to a cutting devicehaving a posterior activation mechanism and an anterior releasemechanism. The posterior activation mechanism requires activation by amotion from the posterior towards the anterior. (e.g., a back buttonthat activates the blade in a manner similar to a ball point pen) andhas a release button in the anterior portion of the housing forretracting the blade. This configuration is advantageous because theactivation of the blade is intuitive and simple since all clinicians arefamiliar with the mechanism for activating a ball point pen. Inaddition, the placement of the release button in the anterior portion ofthe housing allows the device to be made safe without requiring theclinician to look at the device or repositioning the hand after cutting,which allows a clinician to focus on the incision made rather than focuson the safety features of the device.

In some embodiments, the safety cutting device may include an elongatehousing having a lengthwise cavity that extends between an anterioropening and a posterior opening. The cavity is configured to receive aslidable insert and allow movement of the slidable insert in alongitudinal direction. A cutting blade is coupled to the slidableinsert. The housing forms a sheath configured to cover the cuttingblade. The sheath provides the anterior opening through which the bladecan be extended. The slidable insert is moveable within the housingbetween a safe position in which the blade is covered by the sheath andan exposed position in which the blade is extended through the anterioropening and exposed for cutting. A biasing member is operably coupled tothe slidable insert and biases the slidable insert to the safe position.

The safety cutting device also includes a latch mechanism operable tolock the slidable insert in the exposed position. A back button isformed in or coupled to the slidable insert and extends from theposterior opening in the housing, the back button has a rearward facingengagement surface that upon actuation moves the slidable insertlongitudinally from the safe position to the exposed position. Thehousing forms a handle and an front portion of the handle provides agrip for manipulating the cutting device with fingers while performing acutting procedure. A release button is positioned on the anteriorportion of the housing. The release button is configured to unlock thelatch mechanism upon actuation and allow the biasing member to returnthe slidable insert to the safe position.

The release button is positioned near the anterior opening. The releasebutton may be positioned less or equal to 40, 35, 30, 25, 20, 15, or 10mm and/or greater than 5, 10, 15, or 20 mm from the anterior opening ofthe sheath and/or within a range of the foregoing. The release buttonmay also be positioned less than or equal to 50%, 45%, 40%, 35%, 30%,25%, or 20% of the longitudinal distance from the anterior opening tothe posterior opening. The distance between the anterior opening and thebutton is important because there is a natural distance at which aperson will hold the device while cutting. For example, it is awkward tohold the device more than half way from the anterior opening to theposterior opening because the distance reduces the amount of control theuser has when manipulating the device during a cutting procedure. Thus,by placing the release button in the area intended to be gripped by theuser, the release button is in a location where the user can activatethe release button without repositioning the hand following a cuttingprocedure.

In some embodiments, the release button is actuated by an inward forceorthogonal to the longitudinal axis of the housing. Thus, a user canactuate the release button by squeezing in the grip area. The releasebutton may be biased to a non-actuated position thereby requiring acertain amount of force applied by the user to overcome the non-actuatedposition of the release button.

The release button may positioned on a top side (e.g., top side 94) ofthe housing. The top side of the housing is the side opposite thecutting edge of the cutting blade. A user will often place a finger onthe top side of the housing in order to apply force in the downwarddirect to cause cutting. By placing the release button on the top sideof the housing, the release button will be in a convenient position foractuation by the user. Alternatively, the release button may be placedon a bottom side or lateral side of the housing.

In some embodiments the latch mechanism is automatically activated to alocked position when the slidable insert is moved from the safe positionto the activated position. Automatic latching can be important tominimize the number of movements performed by the user. Even when themovement is simple to perform, having too many buttons or mechanisms canmake it difficult for a user to figure out which button performs whichdesired mechanism. In some embodiments, the latch mechanism is activatedby a single motion of the user applying pressure to the back button inthe longitudinal direction. The automatic latch preferably makes aclicking sound to indicate when the latch has been activated. In orderto provide sufficient gripping surface to operate the back button and/orthe release button, the housing may be at least 30 mm, 40 mm 50 mm, 60mm, 70 mm or 80 mm long in the longitudinal direction between theanterior and posterior openings.

With the slidable insert in the exposed position, the back button ispositioned posterior to the anterior opening in the longitudinaldirection. The distance from the anterior opening to back button in thisposition can be important for providing sufficient area for gripping thedevice while activating the blade. In some embodiments, the distancefrom the anterior opening to the back button (with the slidable insertin the exposed position) is greater than or equal to 20, 25, 30, 35, 40,45, 50 mm and optionally less than or equal to 100, 80, 60, or 40 mm orwithin a range of the foregoing points.

The back button may be positioned on a longitudinal post extending fromthe posterior opening. The longitudinal post may be at least 10, 15, 20,25, or 30 mm long and/or less than 50, 45, 40, 35, 30, 25, or 20 mm orwithin a range of the foregoing endpoints.

The back button is preferably protected from accidental activation.Accidental activation may be inhibited or prevented using a protectivecover or a lockout mechanism. Examples of lockout mechanisms that can beused include the lockout mechanisms described in U.S. Pat. No. 5,391,177to Schwartz, U.S. Pat. No. 5,569,282 to Werner, and U.S. Pat. No.6,022,364 to Flumene, all of which are hereby incorporated by reference.

The release button may release the latch mechanism upon actuation or mayinclude a second lock that allows the release button to lock theslidable insert in the exposed position until release of the releasebutton.

Posterior Activation Mechanism and Posterior Cover

A second embodiment relates to a scalpel having a back button thatactivates the blade similar to a ball point pen and has a cover that iscoextensive with the back button to inhibit the slidable insert frombeing accidentally activated.

In some embodiments, the safety cutting device may include an elongatehousing having a lengthwise cavity that extends between an anterioropening and a posterior opening. The cavity is configured to receive aslidable insert and allow movement of the slidable insert in alongitudinal direction. A cutting blade is coupled to the slidableinsert. The housing forms a sheath configured to cover the cuttingblade. The sheath provides the anterior opening through which the bladecan be extended. The slidable insert is moveable within the housingbetween a safe position in which the blade is covered by the sheath andan exposed position in which the blade is extended through the anterioropening and exposed for cutting. A biasing member is operably coupled tothe slidable insert and biases the slidable insert to the safe position.The safety cutting device also includes a latch mechanism operable tolock the slidable insert in the exposed position. A back button isformed in or coupled to the slidable insert and extends from theposterior opening in the housing, the back button has a rearward facingengagement surface that upon actuation moves the slidable insertlongitudinally from the safe position to the exposed position. Aprotective cover partially covers the back button. The protective coverextends from the posterior opening toward the engagement surface for adistance sufficient to impede actuation of the back button by a planarsurface applying a force in the longitudinal direction.

Unless otherwise specified, for purposes of this invention the planarsurface is infinite. Thus, the cover provides a structure that engagesthe planar surface when contacted perpendicular to the longitudinaldirection.

The back button can be angled to provide additional protection againstaccidental activation of forces that are not perpendicular to thelongitudinal direction. The angle of the reward facing surface to theplanar surface may be greater than or equal to 5, 10, 15, 20, or 25degrees and/or less than or equal to 50, 45, 40, 35, 30, or 25 degrees,and/or within a range of the foregoing endpoints. The angle may also bemeasured according to the longitudinal direction, in which case theforegoing angles are subtracted from 90 degrees.

The back button is preferably positioned on a longitudinal postextending from the posterior opening. The longitudinal post may begreater than or equal to 10, 15, 20, 25, or 30 mm long and/or less than50, 45, 40, 35, 30, 25, or 20 mm long or within a range of the foregoingendpoints.

The protective cover preferably extends adjacent to the back buttonand/or the longitudinal post. The distance that the cover needs toextend rearwardly to inhibit a planar surface from exposing the bladewill depend on how far the blade is within the cover. The further theblade is retracted within the cover, the more the back button can bepushed forward without causing exposure of the blade. Nevertheless, insome embodiments, the protective cover may extend rearwardly to aposition adjacent to or posterior to the back button with the slidableinsert in the safe position.

The protective cover may be rigidly fixed to the housing in any mannersuch as adhesive, ultrasonic welding or a snap connection. However, in apreferred embodiment the protective cover is an extension of the housingmaterial (i.e., an integral part of the housing).

The latch mechanism may be automatically activated to a locked positionwhen the slidable insert reaches the exposed position. The latchmechanism may be activated by a single motion of the user applyingpressure to the back button in the longitudinal direction. The latchmechanism may be accomplished using a hook and latch. The cutting devicemay also include a release button to disengage the hook and latch.

The latch mechanism may be formed from something other than a hook andlatch. For example, the latch mechanism may include a guide structurewith a w-shaped groove and a protrusion extending from the slidableinsert into the w-shaped groove. An example of a pen activationmechanism that uses a slidable insert with a w-shaped groove isdisclosed in U.S. Pat. No. 5,571,128 to Shapiro, which is herebyincorporated herein by reference. Another example of a latch mechanismthat may be used with this embodiment of the invention is disclosed inU.S. Pat. No. 5,569,282 to Werner, which is incorporated herein byreference.

Anterior Release Mechanism Fixed Longitudinally

Another embodiment relates to a safety cutting device that includes arelease button with a flange on the slidable insert or housing. In thisembodiment, simple activation and deactivation can be achieved using aminimal number of parts. Minimizing the number of parts may be importantfor facilitating the manufacture and assembly of the device. A releasebutton that is separate from the housing or slidable insert requiresmanufacturing and handling a separate part and often requires multipleparts. In a preferred embodiment the release button is biased to thenon-actuated position. A release buttons that is not formed with aflange will need a separate biasing member (e.g., spring) to keep therelease button in the non-actuated position until user selects theactuated position. Increasing the number of parts can be highlydetrimental to the economic viability of the device.

In some embodiments, the safety cutting device may include an elongatehousing having a lengthwise cavity that extends between an anterioropening and a posterior opening. The cavity is configured to receive aslidable insert and allow movement of the slidable insert in alongitudinal direction. A cutting blade is coupled to the slidableinsert. The housing forms a sheath configured to cover the cuttingblade. The sheath provides the anterior opening through which the bladecan be extended. The slidable insert is moveable within the housingbetween a safe position in which the blade is covered by the sheath andan exposed position in which the blade is extended through the anterioropening and exposed for cutting. A biasing member is operably coupled tothe slidable insert and biases the slidable insert to the safe position.The safety cutting device also includes a latch mechanism operable tolock the slidable insert in the exposed position. A back button isformed in or coupled to the slidable insert and extends from theposterior opening in the housing, the back button has a rearward facingengagement surface that upon actuation moves the slidable insertlongitudinally from the safe position to the exposed position. A releasebutton is formed into the housing or the slidable insert and configuredto unlock the latch mechanism upon actuation. The release button isfixed in the axial direction. In one embodiment, the release button mayinclude a flange formed as a single piece with the slidable insert orthe housing.

In some embodiments, the functions of actuating the back button, lockingthe slidable insert in the exposed position, and unlocking the latchmechanism only requires four separate parts, the parts being a singlepiece slidable insert, a single biasing member such as a spring, and twopieces of housing. In some embodiments, the device can includeadditional parts for performing different functions. However,preferably, the entire device can be made from the four parts and acutting blade.

The latch mechanism may be automatically activated to a locked positionwhen the slidable insert reaches the exposed position. The latchmechanism may be activated by a single motion of the user applyingpressure to the back button in the longitudinal direction.

The back button may be positioned on a longitudinal post extending fromthe posterior opening. The longitudinal post may have dimensions asdescribed above.

The release button may be located on the slidable insert and/or may belocated on a lateral side of the device. An example of a release buttonthat can be used in this embodiment in combination with a pen activationmechanism is shown in U.S. Pat. No. 6,949,109 to Iske, which is herebyincorporated herein by reference.

Latch Mechanism

In yet another embodiment, the cutting device includes a latch mechanismthat locks the slidable insert in the exposed position and the latch isreleased only upon releasing the release button (i.e., pressing therelease button keeps the slidable insert locked and it is only uponrelease of the release button that the latch is disengaged. Once thelatch mechanism is released, the slidable insert is automaticallyreturned to the safe position by the biasing member. In this embodiment,the release button can be pressed down (i.e., initial activation), butthe slidable member is not unlocked until the release button isreleased. This mechanism is advantageous to prevent accidental unlockingof the slidable insert. Preventing accidental unlocking of the slidableinsert allows the release button to be made easy to press down oractuate while positioned in a conspicuous location on the housing orslidable insert, which increases the probability of a clinician usingthe release button and making the device safe.

The cutting device includes an elongate housing having a lengthwisecavity configured to receive the slidable insert. A cutting blade iscoupled to the slidable insert. The housing forms a sheath configured tocover the cutting blade and the sheath has an anterior opening throughwhich the blade can be extended. The slidable insert is moveable withinthe housing in a longitudinal direction between a safe position in whichthe blade is covered by the sheath and an exposed position in which theblade is extended through the anterior opening and exposed for cutting.A biasing member is operably coupled to the slidable insert and biasesthe slidable insert to the safe position. A latch mechanism is operableto lock the slidable insert in the exposed position. The latch mechanismis automatically activated to a locked position by movement of theslidable insert from the safe position to the exposed position.

The housing forms a handle that provides a grip for manipulating thecutting device with fingers during cutting. A release button ispositioned on the handle and has an actuated position and a non-actuatedposition. The release button is biased in the non-actuated position.With the release mechanism positioned in the actuated position therelease mechanism is configured to unlock the latch mechanism andactuate a second lock mechanism that locks the slidable insert in theexposed position, wherein upon release of the release button by a user,the release button automatically returns to the non-actuated positionand unlocks the second lock mechanism, thereby causing the slidableinsert to move to the safe position.

In some embodiments the latch mechanism includes a protrusion positionedon a deflectable member of the slidable insert. The protrusion on thedeflectable member is configured to engage the housing to lock theslidable insert in the exposed position. To unlock the slidable member,the release button is pressed (i.e., actuated). In the actuatedposition, the release button deflects the deflectable member to releasethe lock of the latch.

The second lock mechanism includes a wall on the slidable insert thatengages a protrusion on the release button when the release button is inthe actuated position, thereby locking the slidable insert in theexposed position.

The cutting device may include a back button formed in or coupled to theslidable insert and extending from a posterior opening in the housing.The back button may have a rearward facing engagement surface that uponactuation moves the slidable insert longitudinally from the safeposition to the exposed position.

The invention may also include a method of using a safety scalpel. Themethod includes providing a cutting device as described herein and thenlocking the slidable insert in the exposed position using a latchmechanism, actuating a release button, performing a cutting procedurewith the release button actuated, and releasing the release buttonthereby causing the second lock to disengage and enable the bias memberto move the cutting blade to the covered position.

In an alternative embodiment, the release activated mechanism describedbelow can be incorporated into a slidable insert or housing of any ofthe devices disclosed in U.S. Pat. Nos. 5,571,128; 5,569,282; 6,949,109;or similar devices.

Yet another embodiment relates to a cutting device having anautomatically locking activation mechanism formed from a latch betweenslidable insert and the housing. The device may include a biasing memberpositioned between the housing and the slidable insert. The automaticlocking activation mechanism is unlocked using a release buttonpositioned in the anterior portion of the housing.

The cutting device includes an elongate housing having a lengthwisecavity configured to receive the slidable insert. A cutting blade iscoupled to the slidable insert. The housing forms a sheath configured tocover the cutting blade and the sheath has an anterior opening throughwhich the blade can be extended. The slidable insert is moveable withinthe housing in a longitudinal direction between a safe position in whichthe blade is covered by the sheath and an exposed position in which theblade is extended through the anterior opening and exposed for cutting.A biasing member is operably coupled to the slidable insert and biasesthe slidable insert to the safe position. A latch mechanism is operableto lock the slidable insert in the exposed position. The latch mechanismis automatically activated to a locked position by movement of theslidable insert from the safe position to the exposed position.

The housing forms a handle. A front portion of the handle provides agrip for manipulating the cutting device with fingers during cutting. Arelease button is positioned on the anterior portion of the housing andhas an actuated position and a non-actuated position. The release buttonis biased in the non-actuated position. A release button is positionedon the anterior portion of the housing. The release button is configuredto unlock the latch mechanism upon actuation, thereby causing thebiasing member to return the slidable insert to the safe position.

Any of the foregoing embodiments described above may be used alone or incombination with one another and/or the embodiments disclosed in thereferences incorporated herein by reference.

The illustrative embodiments described in the detailed description andclaims are not meant to be limiting. Other embodiments may be utilized,and other changes may be made, without departing from the spirit orscope of the subject matter presented herein. It will be readilyunderstood that the aspects of the present disclosure, as generallydescribed herein can be arranged, substituted, combined, separated, anddesigned in a wide variety of different configurations, all of which areexplicitly contemplated herein.

The invention claimed is:
 1. A safety cutting device, comprising: anelongate housing defining a sheath having an anterior opening, aposterior opening forming a cavity configured to receive a slidableinsert, and a handle with a posterior end; a cutting blade coupled tothe slidable insert, the slidable insert positioned within the cavityand extended through the posterior opening of the housing to form anactivation mechanism positioned posterior to the handle and theposterior opening, the slidable insert moveable within the housingbetween a safe position in which the blade is covered by the sheath andan exposed position in which the blade is extended through the anterioropening and exposed for cutting, wherein the activation mechanism isconfigured to be engaged by the user to move the slideable insert fromthe safe position to the exposed position, the activation mechanismincluding a rearward facing engagement surface at a posterior endthereof; a protective cover that extends posterior to the posterioropening and the posterior end of the handle and covers the rearwardfacing engagement surface of the activation mechanism to thereby impedesaccidental actuation of the activation mechanism; a biasing memberbiasing the slidable insert to the safe position; a latch mechanismoperable to lock the slidable insert in the exposed position; and arelease mechanism configured to unlock the latch mechanism.
 2. Thecutting device of claim 1, wherein the release mechanism is movable in atransverse direction of the housing and fixed in a longitudinaldirection of the housing.
 3. The cutting device of claim 1, wherein thecutting blade is a number 10 surgical blade.
 4. The cutting device ofclaim 1, wherein the cutting blade is a number 11 surgical blade.
 5. Thecutting device of claim 1, wherein the release mechanism includes aflange integral with the housing and extending along a longitudinaldirection.
 6. The cutting device of claim 1, wherein the releasemechanism is positioned on a top side of the housing opposite a sharpside of the cutting blade.
 7. The cutting device of claim 1, wherein thelatch mechanism automatically locks when the slidable insert reaches theexposed position.
 8. The cutting device of claim 1, further comprising aslot formed in the sheath, the slot configured to cut suture passedtherethrough when the slidable member is in the safe position.
 9. Thecutting device of claim 8, wherein the slot is oriented along alongitudinal direction of the housing.
 10. The cutting device of claim1, wherein the latch mechanism includes a deflectable latch with a hookdisposed at an end thereof, the deflectable latch being disposed on theslidable insert and being biased toward a latch surface of the housing,wherein the hook is configured to engage with the latch surface to lockthe slidable insert in the exposed position.
 11. The cutting device ofclaim 10, wherein the release mechanism includes a protrusion configuredto engage with the deflectable latch when the release mechanism isactuated to thereby disengage the hook from the latch surface to unlockthe slidable insert from the exposed position.
 12. The cutting device ofclaim 1, wherein the release mechanism is positioned within 40 mm fromthe anterior opening.
 13. The cutting device of claim 1, wherein thebiasing member is a coil spring that is compressed when the slideableinsert is in the exposed position.
 14. The cutting device of claim 1,wherein the housing includes a second cavity and the biasing member is acoiled spring disposed in the second cavity.
 15. The cutting device ofclaim 14, wherein the coil spring extends at least 70% of the distancebetween the anterior and posterior openings.
 16. The cutting device ofclaim 1, wherein the housing has a trapezoidal cross section.
 17. Thecutting device of claim 1, wherein the distance between the anterioropening and the posterior opening is in a range from 30-80 mm.
 18. Asafety cutting device, comprising: an elongate housing defining asheath, the elongate housing having an anterior opening and a posterioropening, the elongate housing forming a cavity configured to receive aslidable insert; a cutting blade coupled to the slidable insert, theslidable insert positioned within the cavity and extended through theposterior opening of the elongate housing to form a posterior activationmechanism, the slidable insert moveable within the elongate housingbetween a safe position in which the blade is covered by the sheath andan exposed position in which the blade is extended through the anterioropening and exposed for cutting, wherein the posterior activationmechanism is positioned posterior to the posterior opening andconfigured to be engaged by the user to move the slideable insert fromthe safe position to the exposed position, the posterior activationmechanism including a longitudinal post that extends at least 15 mm fromthe posterior opening and a rearward facing engagement surface at aposterior end of the post; a protective cover that extends from theposterior opening to a position posterior to the rearward facingengagement surface and covers the rearward facing engagement surface tothereby impedes accidental actuation of the posterior activationmechanism; a biasing member biasing the slidable insert to the safeposition; a latch mechanism operable to lock the slidable insert in theexposed position; and a release button positioned on the elongatehousing and providing a surface for actuation thereof, the releasebutton configured to unlock the latch mechanism when actuated.
 19. Asafety cutting device, comprising: an elongate housing defining asheath, the elongate housing having an anterior opening and forming acavity, the cavity configured to receive a slidable insert and a handlewith a posterior end; a cutting blade coupled to the slidable insert,the slidable insert positioned within the cavity and moveable within theelongate housing between a safe position in which the blade is coveredby the sheath and an exposed position in which the blade is extendedthrough the anterior opening and exposed for cutting by an activationmechanism positioned posterior to the handle, the activation mechanismcomprising a rearward facing engagement surface; a protective cover thatextends posterior to the posterior end of the handle and is configuredto cover the rearward facing engagement surface of the activationmechanism to thereby impede accidental actuation of the activationmechanism; a biasing member biasing the slidable insert to the safeposition; a latch mechanism operable to lock the slidable insert in theexposed position, the latch mechanism including a deflectable latchdisposed on the slidable insert and being biased outward toward theelongate housing, wherein the deflectable latch is configured to engagewith a portion of the elongate housing to lock the slidable insert inthe exposed position; and a release mechanism positioned on the elongatehousing and configured to unlock the latch mechanism, the releasemechanism including a flange monolithically formed with the elongatehousing and extending along a longitudinal direction, the flange beingdeflectable in a transverse direction, wherein the flange is configuredto selectively engage with the deflectable latch to disengage thedeflectable latch from the elongate housing and allow the slidableinsert to move to the safe position.
 20. The safety cutting device ofclaim 19, wherein the flange is a single injection molded part of thehousing and has a length of at least 10 mm.